Mental work causes fatigue not because of the quantity but because of the quality of the work.
精神工作导致的疲劳不是因为工作的数量,而是因为工作的质量。
在数学中,提出问题的艺术必须比解决问题更有价值。
"I am not a person who can be easily categorized, and I think that is a good thing."